346 
HYALONEMA (OONEMA) DENSUM. 
to 
o 
t\D 
cn 
CO 
o 
Number 
O 
3 
3 
S' 
four elevations coincide with the four morphological groups above referred to. 
There can be no doubt, therefore, that we have here to deal with four distinct 
kinds of amphidiscs. The group A is very clearly distinguished from all the 
others, both morphologically and biometrically. The group B is clearly dis- 
tinguished morphologically from all other groups, but distinguished biometri- 
Macramphidiscs 
